Azide derivatives

Die Azid-Derivate der Deka- und Dodekaborate stellen farblose kristal-line Salzc dar. 

In another application of coupling proteins to surfaces using click chemistry, Duckworth et al. (2006) carried out prenylation of a protein using a farnesyl azide derivative and the enzyme farnesyl transferase for subsequent chemoselective ligation to alkyne-functionalized agarose beads. The result is a highly discrete, site-specific attachment of the protein to the solid phase at a single location. 

Figure 18.11 NHS-PEG4-azide can be used to modify an amine-containing molecule to create an amide derivative terminating in azido groups. The azide modifications then can be used in a click chemistry reaction that forms a triazole linkage with an alkyne-containing molecule. Alternatively, the azide derivative can be used in a Staudinger ligation reaction with a phosphine derivative, which results in an amide bond linkage.

Shanahan, M.F., Wadzinski, B.E., Lowndes, J.M., and Ruoho, A.E. (1985) Photoaffinity labeling of the human erythrocyte monosaccharide transporter with an aryl azide derivative of D-glucose. J. Biol. Chem. 260, 10897-10900. 

The most frequent synthetic approaches, summarized in Scheme 4, are towards the primary photophores. The preparation of aryl azide derivatives follows the typical retro-synthetic pathway in the majority of the reported cases (Scheme 4 A), and, practically, diazotation is the most commonly used procedure [24 - 29]. In the case of diazirines only one major synthetic sequence is repeated ammonolysis of oximes followed by dehydrogenation (Scheme 4B) [30-32]. There are various ways of preparing diazo- or diazocarbonyl-compounds most frequently the Forster and Bamford-Stevens reactions (Scheme 4C) are employed [33-37]. 

Katzenellenbogen has also studied progesterone receptor with an aryl azide derivative of the hormone (54, Fig. 18). The extremely efficient (60%) photo-covalent attachment was identified in two subunits (B 109 kDa, A 87 kDa) in a ratio of 3.3 1 [147]. 

The photochemical reaction can also proceed via the triplet state and in this case no cyclization is observed. Especially when acetophenone is added as a triplet sensitizer, 41 is not formed. Remarkable is the observation that in the presence of anthracene or pyrene as triplet quencher, the yield of the cyclization product 41 was not enhanced and that nitrene insertion into CH bonds of anthracene or pyrene was observed. When the photochemical cyclization reaction was performed with the tosyl azide derivative 42a or the azido nitrile derivative 42b (Scheme 6), only low yields of the tricyclic amide 41 (32% from 42a, 9% from 42b, respectively) were obtained <2001JCS(PI)2476>. 

The azide derivatives 269 of urocanic acid undergo thermolysis to give 270 in moderate yields, presumably via cyclization of the isocyanate and migration of the alkyl group R (Equation 53) <2002TL5879>. When R is larger than ethyl, a different ring system is formed instead. 

Warren and associates (18) have prepared a glycosyl azide derivative (15) of a heptasaccharide. This glycosyl azide was obtained from O-a-D-manno-pyranosyl-( 1 — 6)-0-[a-D-mannopyranosyl-( 1 — 3)-(9-a-D-mannopyrano syl-(l— 6)-0-a-D - mannopyranosyl - (1 — 3)] - O-fi- d - mannopyranosyl -(1 — 4) - O - (2 - acetamido - 2 - deoxy-/ -d-glucopyranosyl) - (1 — 4) - 2 -acetamido-2-deoxy-D-glucopyranose (12) by treatment of its peracetylated derivative 13 with trimethylsilyl trifuoromethanesulfonate, followed by reaction of the intermediary oxazoline 14 with trimethylsilyl azide. Reduction of the glycosyl azide 15 in the presence of Lindlar catalyst gave the glycosyla-mine derivative 16. The condensation of 16 with 1-tert-butyl N-(9-fluoren-... 

Further interestingly, azide anion (N ), rather weak nucleophile, could easily react with PVC in DA-solvents to give the azide derivatives (equivalent NaN, 60°C, DS (degree of substitution) 64% (hexamethyiphosphortriamide, HMPA), 33% (DMF) and 0%... 

Triazole and 8-azapurine derivatives 843 were prepared by the cyclocondensation of the acyclic azide derivative 842 with cyanoacetamide, norbornadiene, and acetylene derivatives (90H1669). 

Guanyl Azide Derivatives and Salts. See Azidoformamidine under Formamidine in Vol 6, pp FI68-L to F169-R... 

Photolysis of pentacoordinate pentavalent phosphorus azides leads to a Curtius-type reaction36,66. Further investigations into the photolytic behaviour of 25-phosphorus azide derivatives showed that three reaction types can be observed, depending on the nature of the substituents (a) Curtius-type rearrangement (b) tautomeric equilibrium between cyclic and open azides and (c) hydrogen abstraction reaction66. 

Thermally generated nitrene intermediates cyclize in the same way thus 32 was prepared from the azides 31b or 33b in diglyme,42,43 and thermal ring closure of azide derivatives 36b in bis-(2-methoxyethyl) ether afforded 37 in 70-75% yield.46 Other examples include the... 

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